vulnerability / NVI-00012105 / Revision 1
smol-toml: Quadratic-time parse() from parseKey rescanning to end of document on each key line
GitHub lists this reviewed advisory for smol-toml. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
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5.3 medium
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02 / Applicability
The affected context
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smol-toml
source listed<= 1.8.0
### Summary `parse()` has a quadratic-time path in `parseKey`, reachable on default options with ordinary valid input. For every key line and table-header line, `parseKey` (dist/struct.js, lines 58 and 86) finds the dotted-key separator with `ctx.s.indexOf('.', ctx.p)`, where `ctx.s` is the whole document. When a key has no `.` ahead of it, that search runs all the way to the end of the input, and the result is then clamped back to the line terminator `endPtr` - so everything scanned past the current line is wasted. `parseKey` runs once per line, so a document of N dot-free keys costs O(n^2). The most ordinary TOML shape triggers it: a flat list of `key = value` lines, or a repeated `[[a]]` table. No dotted keys, no special options, valid input throughout. ### Proof of concept ```js import { parse } from 'smol-toml' let doc = '' for (let i = 0; i < 256000; i++) doc += 'k' + i + ' = 1\n' console.time('parse') parse(doc) // ~2.8 MB of valid TOML, default options console.timeEnd('parse') ``` Doubling the line count roughly quadruples the time: | lines | size | parse() | |---|---|---| | 32k | 0.3 MB | 0.3 s | | 64k | 0.7 MB | 1.0 s | | 128k | 1.4 MB | 3.5 s | | 256k | 2.8 MB |
03 / Response
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- investigate
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04 / Limits
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05 / Provenance
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- GHSA-r4xh-jqrq-34v2 ↗
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- Revision 1 ·
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